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At least 19 recordsLinked to original sources
PubMed1975

[Diagnosis of human active or latent human brucellosis by lymphocyte transformation. Inhibition of leukocyte migration and passive hemagglutination. Possible interference between brucellosis and some mental disorders].

Passive hemagglutination tests (H.T.), involving the coating of a soluble B. abortus antigen onto sheep red blood cells through chromium chloride, were always negative in non-brucellic subjects. Positive H.T., even at low titers (1:50), were associated with positive specific lymphoblastic (T.T.L.) and inhibition of leucocyte migration (I.M.L.) tests in 13 patients. These 3 tests were negative in 17 control brucellosis-free individuals. Positive H.T. confirmed a clinical diagnosis of brucellosis in 27 patients with dubious or negative responses to classical tests. Low positive (1:50, 1:100) H.T. may correspond to Brucella primary-infection or to a quiescent chronic infection, and higher titers to clinically active brucellosis. There is a correlation between cellular immunity tests (T.T.L., I.M.L.) and passive hemagglutination test. Furthermore, 39/88 women hospitalized in psychiatric wards were positive to H.T., and 6 of them were also highly positive to complement fixation and tube agglutination tests. Three T.T.L. and I.M.L., performed on samples from 3 H.T. (1:50) positive patients, were positive. These 30 patients were classified as depression or severe anorexia.

Adult↗
PubMed1979

Hageman-factor-dependent fibrinolysis: generation of fibrinolytic activity by the interaction of human activated factor XI and plasminogen.

Human coagulation factor XI has been purified, and upon activation with Hageman factor fragments, was found to convert the fibrinolytic proenzyme plasminogen to plasmin. This proactivator activity was shown to be functionally and antigenically distinct from prekallikrein. When the gamma-globulin fractions of plasma deficient in Hageman factor, prekallikrein and factor XI were isolated, factor-XI-deficient plasma possessed two-thirds of the plasminogen proactivator activity of the Hageman-factor-deficient plasma, while prekallikrein deficient plasma had only one-third of the plasminogen proactivator activity. Thus, the Hageman-factor-dependent plasminogen proactivator previously reported to be present in the gamma-globulin fraction of normal human plasma is a function of prekallikrein and factor XI, while the activity observed in prekallikrein-deficient plasma is attributable to factor XI. When compared utilizing digestion of iodinated fibrin, prekallikrein and factor XIa had similar potency per active site; they were, however, far less active than urokinase.

Blood Coagulation Disorders↗
PubMed1979

In vitro assessment of Tc-99m labeled bovine thrombin and streptokinase-activated human plasmin: concise communication.

Bovine thrombin and streptokinase-activated human plasmin have been labeled with Tc-99m using stannous reduction of pertechnetate under physiological conditions (pH 7.4). The binding efficiency of radiotechnetium to these enzymes is greater than 94%, with less than 5% of reduced but unbound Tc-99m (Sn) complex as assayed by ascending paper radiochromatography using ITLC silica gel plate. Free or unbound pertechnetate is less than 1%. In vitro enzymatic analyses of the Tc-99m-labeled enzymes demonstrate no evidence of protein denaturation or significant loss of enzymatic activity after labeling. Both labeled enzymes are biochemically active in vitro with their respective substrates.

Animals↗
PubMed1978

Activated human T lymphocytes display new surface glycoproteins.

We have analyzed the surface glycoproteins of resting and in vitro activated human T lymphocytes by the galactose oxidase/NaB3H4 and the periodate/NaB3H4 labeling techniques. The labeled glycoproteins were separated by polyacrylamide slab gel electrophoresis and visualized by fluorography. A "new" glycoprotein with an apparent molecular weight of 130,000 (GP130) was strongly labeled on alloantigen-activated T blasts but only weakly or not at all on mitogen-stimulated T blasts and resting T lymphocytes. These results demonstrate that human T cells, as earlier found in the mouse system, express different surface molecules in relation to the particular mode of activation and stage of differentiation.

B-Lymphocytes↗
PubMed1978

Evidence that nonspecific inhibitors are induced by soluble products of activated human lymphocytes.

Cultures of lymphocytes stimulated by polyclonal mitogens or specific antigens exhibit an initial wave of cell proliferation followed by a decline which has been explained by the activation of suppressor T cells. This article presents the first results aiming at testing the possibility that the suppressor cells are activated by soluble products released by stimulated lymphocytes. It was found that the supernatants of PHA-activated human lymphocytes stimulate lymphocytes to DNA synthesis with peak responses occurring on day 5 independent of the cell concentration in the cultures. In contrast, the kinetics of lymphocyte responses to phytomitogens or in the mixed lymphocyte culture were found to be dependent on cell concentration; peak responses were delayed at decreasing cell concentrations. The results support the view that certain lymphokines released in stimulated lymphocyte cultures induce suppressor cells and that biologically active concentrations are reached earlier at high cell densities.

Cells, Cultured↗
PubMed1978

Human tumor and rodent-human hybrid cells with an increased number of active human NORs.

A human fibrosarcoma line, HT1080-6TG, with a near diploid number of chromosomes, has an average of 7.3 chromosomes with an Ag-stained nucleolus organizer region (NOR). Cells of this line with an increased number of chromosomes have an increased number of Ag-stained NORs. This cell line has been used as the human parent in constructing mouse-human and rat-human hybrids that segregate rodent chromosomes. The hybrid ccell lines, which have 100 or more chromosomes per cell, show a proportionate increase in the number of Ag-stained NORs (means, 11.4--16.8). The frequency of association of acrocentric chromosomes increases in a similar fashion. There is no evidence of inactivation of human NORs in these cells.

Animals↗
PubMed1978

The ability of smooth and rough strains of Streptococcus pneumoniae to activate human complement by the alternative pathway.

Three capsulate pneumococcal strains of serotypes 1, 2 ans 3, and one non-capsulate strain of serotype 47, were found to activate human complement by the alternative pathway to a similar extent over the concentration range examined. Nevertheless, the capsulate strains, in contrast to the non-capsulate, are known to require complement attachment for phagocytosis and it is therefore postulated that the toxic by-products released cause the wave of oedema characteristic of pneumococcal lobar pneumonia.

Bacteriological Techniques↗
PubMed1978

Autosomal locus regulates inverse relationship between sialic acid content and capacity of mouse erythrocytes to activate human alternative complement pathway.

The observation that mouse erythrocytes (E(m)) from 21 inbred strains had variable capabilities to activate the human alternative complement pathway permitted the demonstration that membrane sialic acid content was inversely related to activating capacity and was regulated by codominant alleles of a single autosomal locus. Linear regression analysis also demonstrated a significant inverse correlation between the sialic acid content of E(m) from four inbred strains and the concentration of beta1H required for decay-dissociation of the properdin-stabilized amplification convertase on the E(m). E(m) from F(1) hybrids derived from strains with high and low alternative pathway activating capacities and from their backcrosses exhibited the alternative pathway activating capacities expected if the activity were regulated by alleles of a single autosomal locus. That this same locus predominantly regulated the sialic acid content of E(m) was established by the significant inverse correlation between the sialic acid content and the alternative pathway activating capacity of E(m) from mice of the F(1) and backcross generations. Although the fluid phase interaction of C3, B, and [unk]D continuously generates C3b in a reaction augmented by properdin, it is the covalent attachment of C3b to bystander surfaces deficient in sialic acid that activates the alternative complement pathway at that site because of impaired binding of beta1H to C3b on such surfaces. Thus, discrimination between activating and nonactivating surfaces occurs after C3b deposition, and sialic acid deficiency represents the molecular basis for our earlier finding that activating particles circumvent the regulatory actions of the control proteins of the alternative pathway.

Animals↗
PubMed1979

Activated T cells in the synovial fluid of arthritic patients: characterization and comparison with in vitro activated human and murine T cells in cooperation with monocytes in cytotoxicity.

Lymphocytes were separated from the synovial fluid of 34 arthritic patients. The majority of lymphocytes rosetted with SRBC and were thus of T origin. A proportion of these cells were activated as indicated by their high 3H-thymidine incorporation in vitro, the formation of "stable" E rosettes, and their ability to attach to autologous monocytes and to human cells. Such attached activated T cells enhanced the cytotoxic activity of monocytes. Human and murine-activated T cells generated in mixed lymphocyte cultures also attached to cell lines of the same species, and after their attachment they enhanced the cytotoxic activity of monocytes and natural killer cells. It is suggested that one of the possible roles of activated T cells in immunologically damaged tissues is the attraction of circulating nonspecific killer cells to the site of the response.

Animals↗
PubMed1976

Identification of albumin as the serum factor essential for the growth of activated human lymphocytes.

Albumin from human, bovine, or rabbit serum supported the growth of concanavalin A-stimulated human thymus-derived lymphocytes equally well. This activity was completely abolished by pepsin digestion. It was shown for bovine serum albumin that the albumin molecule itself, and neither an impurity nor a factor bound to albumin was essential for the growth of lymphocytes. This conclusion was based on observations that the growth-promoting activity could not be removed from albumin, and that the specific activity of albumin remained unaltered after the following procedures: molecular sieving at pH 7.5 at pH 3.0, and in 8 M urea at pH 6.6; ion exchange chromatography at pH 4.3 and in 8 M urea at pH 7.2; isoelectric focusing; charcoal treatment; acetone precipitation; and reduction with 2-mercaptoethanol in the presence of 8 M urea. Dimeric albumin was found to support growth of lymphocytes as well as monomeric albumin, and mercaptalbumin and non-mercaptalbumin were shown to have equal activity.

Animals↗
PubMed1977

Differential effect of vinblastine and colchicine on human active and total T rosettes.

The effect of vinblastine and colchicine on human blood T cell rosette formation with sheep erythrocytes was assessed. For some concentrations, both drugs increased the percentage of active T rosettes. In contrast, the total T rosette percentage was decreased by the same drugs. These experiments further confirm the heterogeneity of T cell rosettes and suggest the existence of three types of sheep red blood cell receptors on human blood T lymphocytes.

Colchicine↗
PubMed1979

Cytotoxic effects of activated human monocytes and lymphocytes to anti-D-treated human erythrocytes in vitro.

Incubation of human monocytes, derived from peripheral blood, with cell-free supernatants from mixed lymphocyte cultures resulted in morphological and functional changes in the mature macrophages. Activation of monocyte-derived macrophages by these factors resulted in a significant increase in their capacity to lyse anti-D-treated human erythrocytes. The lytic activity of both normal and activated macrophages appeared to be independent of erythrophagocytosis. T lymphocytes activated by either allogeneic cells or the mitogen phytohaemagglutinin were not cytolytic to treated erythrocytes even at high effector to target cell ratios.

Antibodies↗
PubMed1977

Adenylate cyclase of GH and ACTH producing tumors of human: activation by non-specific hormones and other bioactive substances.

The adenylate cyclase responses of the human GH or ACTH producing pituitary adenomas and ectopic ACTH producing tumors to TRH, LH-RH, biogenic amines, peptides hormones, PGE1 and rat median eminence extract (MEE) have been examined. Out of 4 GH producing pituitary adenomas obtained from patients with active acromegaly at hypophysectomy two were stimulated by TRH, two by LH-RH, three by norepinephrine, one by dopamine, four by PGE1 and none by serotonin. Glucagon stimulated the adenylate cyclase in one of three and MEE in both of two tested. The positive responses of paradoxical GH release after TRH and/or LH-RH before surgery in these patients coincidentally related to the response of adenylate cyclase of each pituitary adenoma. There seems, however, to be no consistent correlation between the adenylate cyclase responses to biogenic amines and the GH release after L-Dopa or 5-hydroxytroptophan tested. The adenylate cyclase of a pituitary adenoma from case of Cushing's disease was stimulated by LH-RH, norepinephrine glucagon and MEE but not by TRH. Plasma levels of ACTH, beta-MSH and cortisol increased after LH-RH but not after TRH in this patient before hypophysectomy. The adenylate cyclase of two ectopic ACTH producing tumors (gastric carcinoid and malignant thymoma) was activated by TRH, LH-RH, norepinephrine, epinephrine, serotonin, PGE1 and MEE. These results indicate the presence of multiple hormone receptors in GH or ACTH producing pituitary adenomas and ectopic ACTH producing tumors, and suggest that the paradoxical GH or ACTH release after TRH and/or LH-RH injection in acromegaly and Cushing's syndrome might be caused by an alteration of the cellular membrane receptors of the pituitary adenomas.

Acromegaly↗
PubMed1979

Surface glycoproteins of resting and activated human T lymphocytes.

This review summarizes some recent studies on the surface glycoproteins of human thymocytes and T lymphocytes. Purified cells were surface labeled by the galactose oxidase-NaB3H4 or periodate-NaB3H4 techniques. The radioactive membrane glycoproteins were separated by polyacrylamide slab gel electrophoresis and visualized by fluorography. Thymocytes and T lymphocytes show characteristic surface glycoprotein profiles which are easily distinguishable from those of the other main groups of human leukocytes. We observed specific changes in the surface glycoprotein patterns which correlate with the degree of maturation and functional activation of T cells. Surface molecules carrying T cell specific antigens were identified by immune-precipitation from lysates of surface labeled thymocytes and T lymphocytes using rabbit anti-human T cell antibodies. Finally we describe a leukocyte membrane glycoprotein which is a precursor of serum alpha 1 acid glycoprotein (orosomucoid).

Antigens, Surface↗